B 25 Mitchell did not fight in the area where the plane crashed. Only Douglas A-20 Havoc and Consolidated B-24 Liberator.
To be honest it isn't true I'm afraid. In 1944 B-25s of the 4GwAKDD were moved to Konotop ( Ukraina ) and later to Winnica airfield. These planes took part in air raids on Constanța harbour and other Romanian cities. The bombers were used for supporting and delivering supplies for the Jugoslav partisans and the National Liberation Army and Partisan Detachments of Yugoslavia. In the mid of 1944 the 5GwBAD started intensification of such flights. I think their air routes must have run over Romania. Another example of using the B-25 planes is the Jassy–Kishinev offensive. As you may know the most moved frontline to the West was the line between Barlad, Bacau and Piatra Neamt. Does it sound familiar for the crash area?